Methods for modifying therapeutic agents such as therapeutic biomolecules, such as proteins for improved oral, rectal or transmucosal delivery, as well as compositions made using such methods and methods of administering such compositions to a subject, are disclosed. Specifically, the therapeutic agents are conjugated to hyperbranched polymers (HBPs), such as hyperbranched polyglycerol (HPG). When such conjugates are administered orally to a subject, the HBP protects the therapeutic agent from the acid environment of the stomach and protease attack in the gastro-intestinal tract, while facilitating the absorption of the therapeutic agent in the higher pH environment of the intestines. The methods and compositions are useful for the improved administration of a variety of therapeutic agents to a subject.
